Importing Mixamo's FBX in Blender
I also experienced this weird stuff and I was able to solve it.


Select the distorted object
Select Object Tab from Properties Window
Change Transform scale to 0.01
Change Transform X-axis to 90 degrees


Result:
https://www.dropbox.com/s/1yip15gm13dke1c/COnverted.blend?dl=0


Option 2: You may refer to this link if you don't want to do it manually. http://growlybearproductions.com/Blender/
Option 3: You may also change fbx import settings like this (Blender 2.76b)